Medium-term exposure of the North Atlantic copepod Calanus finmarchicus (Gunnerus, 1770) to CO2-acidified seawater: effects on survival and development

• Published in: Biogeosciences
• Main Authors: Pedersen, S. A., Hansen, B. H., Altin, D., Olsen, A. J.
• Format: Text
• Language: English
• Published: 2018
• Subjects: Calanus finmarchicus; North Atlantic
• Online Access: https://doi.org/10.5194/bg-10-7481-2013; https://www.biogeosciences.net/10/7481/2013/

The impact of medium-term exposure to CO 2 -acidified seawater on survival, growth and development was investigated in the North Atlantic copepod Calanus finmarchicus . Using a custom developed experimental system, fertilized eggs and subsequent development stages were exposed to normal seawater (390 ppm CO 2 ) or one of three different levels of CO 2 -induced acidification (3300, 7300, 9700 ppm CO 2 ). Following the 28-day exposure period, survival was found to be unaffected by exposure to 3300 ppm CO 2 , but significantly reduced at 7300 and 9700 ppm CO 2 . Also, the proportion of copepodite stages IV to VI observed in the different treatments was significantly affected in a manner that may indicate a CO 2 -induced retardation of the rate of ontogenetic development. Morphometric analysis revealed a significant increase in size (prosome length) and lipid storage volume in stage IV copepodites exposed to 3300 ppm CO 2 and reduced size in stage III copepodites exposed to 7300 ppm CO 2 . Together, the findings indicate that a p CO 2 level ≤2000 ppm (the highest CO 2 level expected by the year 2300) will probably not directly affect survival in C. finmarchicus . Longer term experiments at more moderate CO 2 levels are, however, necessary before the possibility that growth and development may be affected below 2000 ppm CO 2 can be ruled out.